Page 51 - Build 165

Minimise the use of components with a limited life compared to adjacent materials. An example is using an exterior sealant joint in a concrete panel. A better option would be an open-drained joint that avoids the use of sealant exposed to the weather and UV.
Consider factory-applied nishes instead of site-painted nishes, particularly clear or low-pigment nishes on external timber as these require regular recoating. They can also break down and stain the façade from the paint pigments leaching from the coating.
Consider the location
Designers of MDH should account for the impact of location on maintenance, including component durability in corrosive environ- ments and ongoing operation of adjustable components. An example is metal louvre panels installed in a salt-laden environment.
They may seize up within 5 years due to corrosion unless washed and lubricated annually.
Erosion of painted surfaces, cedar timber and brick mortar by wind-blown sand on coastal buildings is likely, so the prevailing weather direction and orientation of building elevation must be considered.
If there is no easy access, maintenance may never be carried out.
Further factors
Other ways to make MDH easy to maintain include:
● reduce the number of joints that can be a
potential weak point
● specify, where practical, windows that can
be cleaned from the inside or a balcony
or ledge
● facilitate rainwashing of external surfaces
as most materials, especially metals,
perform better when regularly cleaned
● specify surface nishes that are smooth
or glossy as these stay cleaner
● incorporate modular systems that enable
complete replacement as a unit
● use a conservative design to reduce the
risk of water penetration
● consider local fauna – ledges and flat
surfaces on buildings provide roosting places that, if regularly inhabited by birds, mean extra cleaning. In Sydney, cockatoos rip out façade expansion joints, rubber and paint.
Note For more, see Designing for Maintenance, $32.50 from the BRANZ Shop www.branz.
co.nz, BRANZ SR378 The New Zealand Housing Preferences Survey: Attitudes towards medium- density housing and SR386 Maintenance and common repair issues in medium-density housing.
Medium-density housing
Build 165 — April/May 2018 — 49
FEATURE SECTION